Electrooptic system array, charged-particle beam exposure apparatus using the same, and device manufacturing method

ABSTRACT

This invention relates to an electrooptic system array having a plurality of electron lenses. The electrooptic system array includes upper, middle, and lower electrodes arranged along the paths of a plurality of charged-particle beams, the upper, middle, and lower electrodes having pluralities of apertures on the paths of the plurality of charged-particle beams, an upper shield electrode which is interposed between the upper and middle electrodes and has a plurality of shields corresponding to the respective paths of the charged-particle beams, and a lower shield electrode which is interposed between the lower and middle electrodes and has a plurality of shields corresponding to the respective paths of the charged-particle beams.

FIELD OF THE INVENTION

The present invention pertains to the technical field of an electroopticsystem suitable for an exposure apparatus using charged-particle beamssuch as electron beams, and relates to an electrooptic system arrayhaving an array of a plurality of electrooptic systems.

BACKGROUND OF THE INVENTION

In production of semiconductor devices, an electron beam exposuretechnique receives a great deal of attention as a promising candidate oflithography capable of micro-pattern exposure at a line width of 0.1 μmor less. There are several electron beam exposure methods. An example isa variable rectangular beam method of drawing a pattern with one stroke.This method suffers many problems as a mass-production exposureapparatus because of a low throughput. To attain a high throughput,there is proposed a pattern projection method of reducing andtransferring a pattern formed on a stencil mask. This method isadvantageous to a simple repetitive pattern but disadvantageous to arandom pattern such as a logic interconnection pattern in terms of thethroughput, and a low productivity disables practical application.

To the contrary, a multi-beam system for drawing a patternsimultaneously with a plurality of electron beams without using any maskhas been proposed and is very advantageous to practical use because ofthe absence of physical mask formation and exchange. What is importantin using a multi-electron beams is the number of electron lens arraysused in this system. The number of electron lenses formed in an arraydetermines the number of beams, and is a main factor which determinesthe throughput. Downsizing the electron lenses while improving theperformance of them is one of keys to improving the performance of themulti-beam exposure apparatus.

Electron lenses are classified into electromagnetic and electrostatictypes. The electrostatic electron lens does not require any coil core orthe like, is simpler in structure than the electromagnetic electronlens, and is more advantageous to downsizing. Principal prior artsconcerning downsizing of the electrostatic electron lens (electrostaticlens) will be described.

A. D. Feinerman et al. (J. Vac. Sci. Technol. A10(4), p. 611, 1992)disclose a three-dimensional structure made up of three electrodes as asingle electrostatic lens by a micromechanical technique using aV-groove formed by a fiber and Si crystal anisotropic etching. The Sifilm has a membrane frame, membrane, and aperture formed in the membraneso as to transmit an electron beam. K. Y. Lee et al. (J. Vac. Sci.Technol. B12(6), p. 3,425, 1994) disclose a multilayered structure of Siand Pyrex glass fabricated by using anodic bonding. This techniquefabricates microcolumn electron lenses aligned at a high precision.Sasaki (J. Vac. Sci. Technol. 19, p. 963, 1981) discloses an Einzel lensmade up of three electrodes having lens aperture arrays. Chang et al.(J. Vac. Sci. Technol. B10, p. 2,743, 1992) disclose an array ofmicrocolumns having Einzel lenses.

In the prior arts, if many aperture electrodes are arrayed, anddifferent lens actions are applied to electron beams, the orbit andaberration change under the influence of the surrounding electrostaticlens field, and so-called crosstalk occurs in which electron beams aredifficult to operate independently.

Crosstalk will be explained in detail with reference to FIG. 10. Threetypes of electrodes, i.e., an upper electrode 1, middle electrodes 2,and a lower electrode 3 constitute an Einzel lens. The upper and lowerelectrodes 1 and 3 are 10 μm in thickness and have 80-μm diameterapertures arrayed at a pitch of 200 μm. The middle electrodes 2 are 50μm in thickness, have a cylindrical shape 80 μm in inner diameter, andarrayed at a pitch of 200 μm. The distances between the upper and middleelectrodes 1 and 2 and between the middle and lower electrodes 2 and 3are 100 μm. The upper and lower electrodes 1 and 3 receive a potentialof 0 [V], middle electrodes 2 on central and upper rows B and A receive−1,000 [V], and middle electrodes 2 on a lower row C receive −950 [V].The potential difference between adjacent electrodes is 50 [V]. When anelectron beam having a beam diameter of 40 μm and an energy of 50 keVenters a central aperture from the left of the upper electrode 1, adownward shift angle Δθ of the electron beam becomes several ten μrad ormore. A typical allowable value of the shift angle Δθ is 1 μrad or less.In this electrode arrangement, the shift angle exceeds the allowablerange. That is, the electron beam is influenced by the surrounding lensfield, and so-called crosstalk occurs, which must be solved.

SUMMARY OF THE INVENTION

The present invention has been made to overcome the conventionaldrawbacks, and has as its principal object to provide an improvement ofthe prior arts. It is an object of the present invention to provide anelectrooptic system array which realizes various conditions such asdownsizing, high precision, and high reliability at high level. It isanother object of the present invention to provide an electroopticsystem array improved by reducing crosstalk unique to a multi-beam. Itis still another object of the present invention to provide ahigh-precision exposure apparatus using the electrooptic system array, ahigh-productivity device manufacturing method, a semiconductor deviceproduction factory, and the like.

According to the first aspect of the present invention, there isprovided an electrooptic system array having a plurality of electronlenses, comprising at least two electrodes arranged along paths of aplurality of charged-particle beams, each of at least two electrodeshaving a plurality of apertures on the paths of the plurality ofcharged-particle beams, and a shield electrode which is interposedbetween at least two electrodes and has a plurality of shieldscorresponding to the respective paths of the plurality ofcharged-particle beams.

According to a preferred mode of the present invention, each shield hasan aperture on a path of a corresponding charged-particle beam, and/orthe shield electrode is constituted by integrating the plurality ofshields. According to another preferred mode of the present invention,the shield electrode may be insulated from at least two electrodes ormay be integrated with one of at least two electrodes. According tostill another preferred mode of the present invention, the plurality ofshields of the shield electrode receive the same potential, and/orreceive a potential different from a potential applied to at least twoelectrodes. According to still another preferred mode of the presentinvention, the aperture of each shield of the shield electrode is largerin size than the apertures of at least two electrodes. According tostill another preferred mode of the present invention, at least twoelectrodes include first and second electrodes, each of the first andsecond electrodes has a plurality of electrode elements with apertureson the paths of the plurality of charged-particle beams, the pluralityof electrode elements of the first electrode are grouped in units ofrows in a first direction, electrode elements which belong to each groupbeing connected, and the plurality of electrode elements of the secondelectrode are grouped in units of rows in a second direction differentfrom the first direction, electrode elements which belong to each groupbeing connected.

According to the second aspect of the present invention, there isprovided an electrooptic system array having a plurality of electronlenses, comprising upper, middle, and lower electrodes arranged alongpaths of a plurality of charged-particle beams, the upper, middle, andlower electrodes having pluralities of apertures on the paths of theplurality of charged-particle beams, an upper shield electrode which isinterposed between the upper and middle electrodes and has a pluralityof shields corresponding to the respective paths of the plurality ofcharged-particle beams, and a lower shield electrode which is interposedbetween the lower and middle electrodes and has a plurality of shieldscorresponding to the respective paths of the plurality ofcharged-particle beams.

According to a preferred mode of the present invention, the middleelectrode includes a plurality of electrode elements having apertures onthe paths of the plurality of charged-particle beams. According toanother preferred mode of the present invention, the electrooptic systemarray preferably further comprises a middle shield electrode between theplurality of electrode elements of the middle electrode. According tostill another preferred mode of the present invention, it is preferablethat the plurality of electrode elements of the middle electrode begrouped in units of, e.g., rows, and electrode elements which belong toeach group be electrically connected to each other. Alternatively, it ispreferable that the middle electrode have a plurality of rectangularelectrode units electrically separated in units of rows, and eachelectrode unit have a plurality of apertures on the paths ofcorresponding charged-particle beams. According to still anotherpreferred mode of the present invention, the respective shields of theupper and lower shield electrodes preferably have apertures on the pathsof the charged-particle beams. According to still another preferred modeof the present invention, it is preferable that the upper shieldelectrode be constituted by integrating the plurality of shields, andthe lower shield electrode be constituted by integrating the pluralityof shields. According to still another preferred mode of the presentinvention, it may be possible that the upper shield electrode isinsulated from the upper and middle electrodes, and the lower shieldelectrode is insulated from the lower and middle electrodes, or that theupper shield electrode is integrated with the upper electrode, and thelower shield electrode is integrated with the lower electrode. Accordingto still another preferred mode of the present invention, the pluralityof shields of the upper shield electrode and the plurality of shields ofthe lower shield electrode receive the same potential, and/or receive apotential different from a potential applied to the upper and lowerelectrodes. According to still another preferred mode of the presentinvention, an aperture of each shield of the upper shield electrode andan aperture of each shield of the lower shield electrode are larger insize than an aperture of the middle electrode. According to stillanother preferred mode of the present invention, an interval between themiddle electrode and the upper shield electrode and an interval betweenthe middle electrode and the lower shield electrode are smaller than apitch of a plurality of apertures of the middle electrode.

According to the third aspect of the present invention, there isprovided a charged-particle beam exposure apparatus comprising acharged-particle beam source for emitting a charged-particle beam, anelectrooptic system array which has a plurality of electron lenses andforms a plurality of intermediate images of the charged-particle beamsource by the plurality of electron lenses, and a projectionelectrooptic system for projecting on a substrate the plurality ofintermediate images formed by the electrooptic system array, theelectrooptic system array including at least two electrodes arrangedalong paths of a plurality of charged-particle beams, each of at leasttwo electrodes having a plurality of apertures on the paths of theplurality of charged-particle beams, and a shield electrode which isinterposed between at least two electrodes and has a plurality ofshields corresponding to the respective paths of the plurality ofcharged-particle beams.

According to the fourth aspect of the present invention, there isprovided a charged-particle beam exposure apparatus comprising acharged-particle beam source for emitting a charged-particle beam, anelectrooptic system array which has a plurality of electron lenses andforms a plurality of intermediate images of the charged-particle beamsource by the plurality of electron lenses, and a projectionelectrooptic system for projecting on a substrate the plurality ofintermediate images formed by the electrooptic system array, theelectrooptic system array including upper, middle, and lower electrodesarranged along paths of a plurality of charged-particle beams, theupper, middle, and lower electrodes having pluralities of apertures onthe paths of the plurality of charged-particle beams, an upper shieldelectrode which is interposed between the upper and middle electrodesand has a plurality of shields corresponding to the respective paths ofthe plurality of charged-particle beams, and a lower shield electrodewhich is interposed between the lower and middle electrodes and has aplurality of shields corresponding to the respective paths of theplurality of charged-particle beams.

According to the fifth aspect of the present invention, there isprovided a device manufacturing method comprising the steps ofinstalling a plurality of semiconductor manufacturing apparatusesincluding the charged-particle beam exposure apparatus in a factory, andmanufacturing a semiconductor device by using the plurality ofsemiconductor manufacturing apparatuses. In this case, thismanufacturing method preferably further comprises the steps ofconnecting the plurality of semiconductor manufacturing apparatuses by alocal area network, connecting the local area network to an externalnetwork of the factory, acquiring information about the charged-particlebeam exposure apparatus from a database on the external network by usingthe local area network and the external network, and controlling thecharged-particle beam exposure apparatus on the basis of the acquiredinformation.

According to the sixth aspect of the present invention, there isprovided a semiconductor manufacturing factory comprising a plurality ofsemiconductor manufacturing apparatuses including the charged-particlebeam exposure apparatus, a local area network for connecting theplurality of semiconductor manufacturing apparatuses, and a gateway forconnecting the local area network to an external network of thesemiconductor manufacturing factory.

According to the seventh aspect of the present invention, there isprovided a maintenance method for a charged-particle beam exposureapparatus, comprising the steps of preparing a database for storinginformation about maintenance of the charged-particle beam exposureapparatus on an external network of a factory where the charged-particlebeam exposure apparatus is installed, connecting the charged-particlebeam exposure apparatus to a local area network in the factory, andmaintaining the charged-particle beam exposure apparatus on the basis ofthe information stored in the database by using the external network andthe local area network.

Other features and advantages of the present invention will be apparentfrom the following description taken in conjunction with theaccompanying drawings, in which like reference characters designate thesame or similar parts throughout the figures thereof.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated in and constitute apart of the specification, illustrate embodiments of the invention and,together with the description, serve to explain the principles of theinvention.

FIGS. 1A to 1D are views for explaining the structure of an electroopticsystem array;

FIGS. 2A to 2F are sectional views for explaining a method offabricating an upper electrode (lower electrode) and shield electrode;

FIGS. 3A to 3D are sectional views for explaining a method offabricating a middle electrode;

FIGS. 4A to 4D are sectional views for explaining a method of joiningelectrodes;

FIG. 5 is a sectional view for explaining a state in which theelectrodes are completely joined;

FIG. 6 is a sectional view for explaining another structure of anelectrooptic system array;

FIGS. 7A to 7C are views for explaining still another structure of anelectrooptic system array;

FIGS. 8A to 8D are views for explaining still another structure of anelectrooptic system array;

FIGS. 9A to 9C are views for explaining still another structure of anelectrooptic system array;

FIG. 10 is a view for explaining generation of crosstalk;

FIGS. 11A to 11E are views for explaining still another structure of anelectrooptic system array;

FIGS. 12A and 12B are views for explaining still another structure of anelectrooptic system array;

FIG. 13 is a view showing an entire multi-beam exposure apparatus;

FIGS. 14A and 14B are views for explaining details of a correctionelectrooptic system;

FIG. 15 is a view showing the concept of a semiconductor deviceproduction system when viewed from a given angle;

FIG. 16 is a view showing the concept of the semiconductor deviceproduction system when viewed from another angle;

FIG. 17 is a view showing a user interface on a display;

FIG. 18 is a flow chart for explaining the flow of a semiconductordevice manufacturing process; and

FIG. 19 is a flow chart for explaining details of a wafer process.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

<Electrooptic System Array>

An electrooptic system array according to an embodiment of the presentinvention will be described. FIG. 1A is an exploded sectional view ofthe electrooptic system array. The electrooptic system array shown inFIG. 1A is constituted by sequentially stacking, on the paths of aplurality of electron beams (charged-particle beams), an upper electrode1, upper shield electrode 4, middle electrode 2, lower shield electrode5, and lower electrode 3, each of which has a plurality of apertures.FIG. 1B is a plan view of the upper electrode 1 when viewed from thetop, FIG. 1C is a plan view of the upper shield electrode 4 when viewedfrom the top, and FIG. 1D is a plan view of the middle electrode 2 whenviewed from the top.

The upper electrode 1 has a thin-film structure 10 μm in thickness thatis formed from an electrode layer of a conductive material (e.g., Cu orAu), and has a plurality of 80-μm diameter circular apertures 8 arrayedregularly at a pitch of 200 μm. The lower electrode 3 also has the samestructure, and has a plurality of apertures 14 at positionscorresponding to the apertures of the upper electrode. The middleelectrode 2 comprises cylindrical electrode elements (aperturedelectrode elements) 11 of a conductive material (e.g., Cu or Au)(thickness: 50 μm, inner diameter: 80 μm, outer diameter: 170 μm) havingapertures 10. The cylindrical electrode elements 11 are grouped in unitsof rows (rows A, B, and C), and cylindrical electrode elements 11included in each row are electrically connected by a wiring line 12 ofCu, Au, or the like with a width of 4 μm. The upper and lower shieldelectrodes 4 and 5 respectively have circular apertures 9 and 13 with aninner diameter of 160 μm that are formed in an 88-μm thick conductive(e.g., Cu or Au) plate regularly at a pitch of 200 μm. The sizes (innerdiameter sizes) of the apertures of the upper and lower shieldelectrodes 4 and 5 are larger than those of the middle, upper, and lowerelectrodes 2, 1, and 3. This reduces the influence of inserting theshield electrode on lens action.

The apertures regularly arrayed in the upper electrode 1, upper shieldelectrode 4, middle electrode 2, shield electrode 5, lower electrode 3,and middle electrode 2 are formed on the paths of electron beams suchthat the centers of the apertures coincide with each other when viewedalong the optical axis. The upper electrode 1 and upper shield electrode4 are joined via an insulating layer 6, whereas the lower electrode 3and lower shield electrode 5 are joined via an insulating layer 7. Theinsulating layers 6 and 7 are 1 μm in thickness, so that the distancesbetween the upper electrode 1 and the upper shield electrode 4 andbetween the lower electrode 3 and the lower shield electrode 5 are 1 μm.The distances between the upper and middle electrodes 1 and 2 andbetween the lower and middle electrodes 3 and 2 are 100 μm. The uppershield electrode 4 is insulated from the middle electrode 2, while thelower shield electrode 5 is insulated from the middle electrode 2.

In the electrooptic system array having this arrangement, similar toFIG. 10, the upper electrode 1, upper shield electrode 4, lower shieldelectrode 5, and lower electrode 3 receive a potential of 0 [V], row B(central row) and row A of the middle electrode 2 receive a potential of−1,000 [V], and row C of the middle electrode 2 receives a potential of−950 [V]. The adjacent potential difference between rows B and C is 50[V]. At this time, the beam shift angle Δθ is 0.8 mμrad, and the beamdiameter (least circle of confusion) is 0.6 μm, which fall within theirallowable ranges and are suppressed to a negligible degree in practicaluse.

According to this embodiment, the shield electrodes 4 and 5 arerespectively interposed between the upper and middle electrodes 1 and 2and between the middle and lower electrodes 2 and 3 in correspondencewith a plurality of apertures in the electrooptic system array havingthe upper, middle, and lower electrodes 1, 2, and 3 which havepluralities of apertures and are stacked along the electron beam path.This structure can suppress the influence of an adjacent lens field andcan satisfactorily suppress crosstalk.

A method of fabricating an electrooptic system array having the abovestructure will be explained. For descriptive convenience, only oneaperture will be exemplified.

A method of fabricating a structure made up of the upper electrode 1 andupper shield electrode 4 will be described with reference to FIGS. 2A to2F. A structure made up of the lower electrode 3 and lower shieldelectrode 5 can also be formed by the same method.

A silicon wafer 101 of the <100> direction is prepared as a substrate,and 300-nm thick silicon nitride films are formed on the respectivesurfaces of the silicon wafer 101 by CVD (Chemical Vapor Deposition). Byresist and etching processes, patterned silicon nitride films 102 and103 are formed as a result of removing the silicon nitride films at aportion serving as a prospective optical path of an electron beam and aportion used to align electrodes (FIG. 2A).

The silicon substrate 101 is anisotropically etched to a depth of 1 to 2μm with an aqueous tetramethylammonium hydroxide solution using thesilicon nitride films 102 and 103 as a mask, thus forming V-grooves 104in at least one surface of the substrate. Chromium and gold films aresuccessively deposited to film thicknesses of 50 nm and 1 μm as an upperelectrode 105 (corresponding to 1 in FIG. 1A) on the surface having theV-grooves 104. A resist pattern is formed on these films, and the goldand chromium films are etched using the resist pattern as a mask,thereby forming an electron beam aperture 106 (FIG. 2B).

An SiO₂ film (insulating film) 107 is sputtered to 1 μm and patterned.Chromium and gold films are successively deposited to film thicknessesof 5 nm and 50 nm as a plating electrode film 108 for forming an uppershield electrode 110 (corresponding to 4 in FIG. 1A), and patterned(FIG. 2C).

A resist pattern 109 serving as a plating mold is formed on the platingelectrode 108. More specifically, the resist is made of SU-8 (MicroChem.Co) mainly consisting of an epoxidized bisphenol A oligomer, and isformed to a film thickness of 110 μm. Exposure employs a contact typeexposure apparatus using a high-pressure mercury lamp. After exposure,post-exposure bake (PEB) is done on a hot plate at 85° C. for 30 min.After the substrate is gradually cooled to room temperature, the resistis developed with propylene glycol monomethyl ether acetate for 5 min tocomplete the plating mold pattern 109. An 89-μm thick gold pattern 110serving as an upper shield electrode (corresponding to 4 in FIG. 1A) isburied in the apertures of the resist pattern 109 by electroplating(FIG. 2D).

The SU-8 resist 109 is removed, and the substrate is cleaned and driedby IPA (FIG. 2E).

The plating surface is protected with polyimide (not shown). The siliconsubstrate 101 is etched back from the other surface at 90° C. with a 22%aqueous tetramethylammonium hydroxide solution. Etching is continueduntil silicon is etched away and the silicon nitride film 102 isexposed. The substrate is cleaned with water and dried. The siliconnitride film 102 exposed after etching of silicon is etched away byusing tetrafluoromethane in a dry etching apparatus. The polyimide filmwhich protects the other surface is removed by ashing (FIG. 2F).

The middle electrode 2 is fabricated as follows. A silicon wafer isprepared as a substrate 201, and an SiO₂ film 202 is formed to athickness of 50 nm by sputtering. A plating electrode film 203 forfabricating a middle electrode 205 (corresponding to 2 in FIG. 1A) isformed by depositing gold to a film thickness of 50 nm and patterning it(FIG. 3A).

A resist pattern 204 serving as a plating mold is formed. Morespecifically, the resist is made of SU-8 (MicroChem. Co) mainlyconsisting of an epoxidized bisphenol A oligomer, and is formed to afilm thickness of 80 μm. Exposure employs a contact type exposureapparatus using a high-pressure mercury lamp. After exposure,post-exposure bake (PEB) is done on a hot plate at 85° C. for 30 min.After the substrate is gradually cooled to room temperature, the resistis developed with propylene glycol monomethyl ether acetate for 5 min tocomplete the plating mold pattern 204 (FIG. 3B).

A 50-μm thick gold pattern 205 is buried as the middle electrode(corresponding to 2 in FIG. 1A) in the apertures of the resist pattern204 by electroplating (FIG. 3C).

The SU-8 resist 204 is removed in N-methyl-pyrrolidone (NMP), and thesubstrate is cleaned and dried by IPA (FIG. 3D).

A method of joining the middle electrode and a structure made up of alower electrode and lower shield electrode will be explained withreference to FIGS. 4A to 4D. As described above, the structure made upof the lower electrode and lower shield electrode is fabricated by thesame method as the method of fabricating the structure made up of theupper electrode and upper shield electrode.

A lower electrode and lower shield electrode shown in FIG. 2F that arefabricated by the procedures of FIGS. 2A to 2F are prepared. After anSiO₂ film (insulating film) 111 is formed to 10 μm by sputtering andpatterned, a gold film 112 is deposited to 50 nm and patterned (FIG.4A). The middle electrode prepared by the procedures shown in FIGS. 3Ato 3D is turned over and pressed against the gold film 112 bygold-to-gold contact bonding (FIGS. 4B and 4C). Only the silicon waferof the middle electrode is wet-etched with a jig. The gold and SiO₂films are sequentially dry-etched away by 50 nm each to obtain a lowerelectrode/middle electrode structure (FIG. 4D).

FIG. 5 is a view for explaining the final assembly. The structure shownin FIG. 4D that is fabricated by the procedures shown in FIGS. 4A to 4Dand constituted by the joined lower electrode 105 (corresponding to 3 inFIG. 1A), lower shield electrode 110 (corresponding to 5 in FIG. 1A),and middle electrode 205 (corresponding to 11 in FIG. 1A) faces thestructure shown in FIG. 2F that is fabricated by the procedures shown inFIGS. 2A to 2F and constituted by the upper electrode 105 (correspondingto 1 in FIG. 1A) and upper shield electrode 110 (corresponding to 4 inFIG. 1A). Fibers 20 are set in the alignment V-grooves 104 formed on thetwo sides of the substrate. The two structures are pressed to achievealignment in directions parallel and perpendicular to the joinedsurface. The aligned members are fixed with an adhesive. Accordingly, anelectrooptic element array with high assembly precision is completed.

Several modifications of the above-described electrooptic system arraywill be explained. FIG. 6 is an exploded view showing an arrangementhaving a plurality of middle electrodes. Compared to the embodiment ofFIG. 1A using one middle electrode, the electrooptic system array ofFIG. 6 has two middle electrodes 2A and 2B which sandwich a middleshield electrode 15.

FIGS. 7A to 7C show another embodiment of an electrooptic system arrayin which a shield electrode is not separate but is integrated into oneelectrode. FIG. 7A is an exploded sectional view of the electroopticsystem array, FIG. 7B is a plan view of a middle electrode 2 when viewedfrom the top, and FIG. 7C is a perspective view of a lower electrode 3,lower shield 5, upper electrode 1, and upper shield 4. In thiselectrooptic system array, the upper electrode 1 and upper shieldelectrode 4 and the lower electrode 3 and lower shield electrode 5 areintegrated structures of a metal material, respectively, and noinsulating layer is interposed in each electrode and a correspondingshield electrode. This can simplify the manufacturing process.

FIGS. 8A to 8D show an electrooptic system array having still anotherstructure. FIG. 8A is an exploded sectional view of the electroopticsystem array, FIG. 8B is a plan view of a middle electrode 2 when viewedfrom the top, FIG. 8C is a sectional view of the middle electrode 2, andFIG. 8D is a perspective view of a lower electrode 3, lower shield 5,upper electrode 1, and upper shield 4. Middle shield electrodes 16 arearranged between a plurality of cylindrical electrode elements of themiddle electrode 2. This reduces the influence of an adjacent electricfield in the cylindrical electrode elements of the middle electrode 2,and improves the anti-crosstalk effect.

FIGS. 9A to 9C show an electrooptic system array having still anotherstructure. A middle electrode 2 comprises a plurality of rectangularelectrode elements 2A, 2B, and 2C arrayed in units of rows, whichenables applying different potentials to the respective arrays. Theserectangular electrode elements increase the rigidity of the structureand also increase the process precision.

FIGS. 11A to 11E are views showing an electrooptic system arrayaccording to still another embodiment. FIG. 11A is a sectional view ofthe electrooptic system array which has an upper, middle, and lowerelectrodes 1, 2, and 3 each having a plurality of aperture electrodes.Upper and lower shield electrodes 4 and 5 set to a common potential arearranged to sandwich the aperture electrodes (electrode elements) of themiddle electrode 2. The aperture electrodes of the upper and lowershield electrodes 4 and 5 are arranged on the electron beam path. Theelectrodes 1, 2, and 3 and the shields 4 and 5 are stacked andintegrated via insulating spacers 20. FIG. 11B shows the structure ofthe upper or lower electrode 1 or 3 in which all the aperture electrodesare grounded to a potential of 0 [V]. FIG. 11C shows the structure ofthe upper or lower shield electrode 4 or 5 in which a common potentialVs (e.g., −500 V) is applied to all the aperture electrodes. FIG. 11Dshows the structure of the middle electrode 2 in which differentpotentials V1, V2, and V3 (e.g., V1=−900 V, V2=−950 V, and V3=−1,000 V)are applied in units of rows of the aperture electrodes. Einzel lenseshaving middle electrodes on different rows exhibit different lensactions, and the middle electrodes can be regarded as setting electrodesfor setting the lens actions of the Einzel lenses. The potentials may beapplied in this manner not only in this arrangement but also in theother arrangements described above.

To effectively reduce crosstalk, intervals s between the middleelectrode 2 and the upper and lower shield electrodes 4 and 5 are setsmaller than a layout interval (pitch) p between aperture electrodesformed in the middle electrode 2, as shown in FIG. 11A. To reduce theinfluence of inserting the shield electrode on lens action, an aperturesize Ds (inner diameter) of each electrode in the shield electrode 4 or5 (see FIG. 1C) is set larger than an aperture size Dc (inner diameter)of each electrode in the middle electrode 2 (see FIG. 1D). The aperturesize of each electrode of the shield electrode 4 or 5 is set larger thanthe aperture size of each electrode of the upper or lower electrode 1 or3.

Instead of this structure, the middle electrode may be constituted asshown in FIG. 1E. In FIG. 1E, the middle electrode 2 comprises middleshield electrodes 15 linearly formed between the rows of electrodeelements 11 set to different potentials (V1, V2, and V3). The middleshield electrodes 15 receive the same common potential Vs as the shieldelectrodes 4 and 5. Crosstalk is effectively prevented by shielding theelectrode rows from each other within the middle electrode.

FIGS. 12A and 12B show still another modification. This modificationadopts an integrated structure of a unit LA1 including a middleelectrode 24 on which rows of electrode elements 11 are formed in the Ydirection, and a unit LA2 including a middle electrode 27 on which rowsof electrode elements 11 are formed in the perpendicular X direction.One electrode 22 serves as both the lower electrode of the unit LA1 andthe upper electrode of the unit LA2. An upper electrode 21, theelectrode 22, and a lower electrode 23 are grounded, and a total of fourshield electrodes 25, 26, 28, and 29 receive the same potential Vs.

<Electron Beam Exposure Apparatus>

A multi-beam charged-particle exposure apparatus (electron beam exposureapparatus) will be exemplified as a system using an electrooptic systemarrays as described in the various embodiments. FIG. 13 is a schematicview showing the overall system. In FIG. 13, an electron gun 501 as acharged-particle source is constituted by a cathode 501 a, grid 501 b,and anode 501 c. Electrons emitted by the cathode 501 a form a crossoverimage (to be referred to as an electron source ES hereinafter) betweenthe grid 501 b and the anode 501 c. An electron beam emitted by theelectron source ES irradiates a correction electrooptic system 503 viaan irradiation electrooptic system 502 serving as a condenser lens. Theirradiation electrooptic system 502 is comprised of electron lenses(Einzel lenses) 521 and 522 each having three aperture electrodes. Thecorrection electrooptic system 503 includes an electrooptic system arrayto which the electrooptic system arrays are applied, and forms aplurality of intermediate images of the electron source ES (details ofthe structure will be described later). The correction electroopticsystem 503 adjusts the formation positions of intermediate images so asto correct the influence of aberration of a projection electroopticsystem 504. Each intermediate image formed by the correctionelectrooptic system 503 is reduced and projected by the projectionelectrooptic system 504, and forms an image of the electron source ES ona wafer 505 as a surface to be exposed. The projection electroopticsystem 504 is constituted by a symmetrical magnetic doublet made up of afirst projection lens 541 (543) and second projection lens 542 (544).Reference numeral 506 denotes a deflector for deflecting a plurality ofelectron beams from the correction electrooptic system 503 andsimultaneously displacing a plurality of electron source images on thewafer 505 in the X and Y directions; 507, a dynamic focus coil forcorrecting a shift in the focal position of a light source image causedby deflection aberration generated when the deflector 506 operates; 508,a dynamic stigmatic coil for correcting astigmatism among deflectionaberrations generated by deflection; 509, a θ-Z stage which supports thewafer 505, is movable in the optical axis AX (Z-axis) direction and therotational direction around the Z-axis, and has a stage reference plate510 fixed thereto; 511, an X-Y stage which supports the θ-Z stage and ismovable in the X and Y directions perpendicular to the optical axis AX(Z-axis); and 512, a reflected-electron detector for detecting reflectedelectrons generated upon irradiating a mark on the stage reference plate510 with an electron beam.

FIGS. 14A and 14B are views for explaining details of the correctionelectrooptic system 503. The correction electrooptic system 503comprises an aperture array AA, blanker array BA, element electroopticsystem array unit LAU, and stopper array SA along the optical axis. FIG.14A is a view of the correction electrooptic system 503 when viewed fromthe electron gun 501, and FIG. 14B is a sectional view taken along theline A-A′ in FIG. 14A. As shown in FIG. 14A, the aperture array AA hasan array (8×8) of apertures regularly formed in a substrate, and splitsan incident electron beam into a plurality of (64) electron beams. Theblanker array BA is constituted by forming on one substrate a pluralityof deflectors for individually deflecting a plurality of electron beamssplit by the aperture array AA. The element electrooptic system arrayunit LAU is formed from first and second electrooptic system arrays LA1and LA2 as electron lens arrays each prepared by two-dimensionallyarraying a plurality of electron lens on the same plane. Theelectrooptic system arrays LA1 and LA2 have a structure as anapplication of the electrooptic system arrays described in the aboveembodiments to an 8×8 array. The first and second electrooptic systemarrays LA1 and LA2 are fabricated by the above-mentioned method. Theelement electrooptic system array unit LAU constitutes one elementelectrooptic system EL by the electron lenses of the first and secondelectrooptic system arrays LA1 and LA2 that use the common X-Ycoordinate system. The stopper array SA has a plurality of aperturesformed in a substrate, similar to the aperture array AA. Only a beamdeflected by the blanker array BA is shielded by the stopper array SA,and ON/OFF operation of an incident beam to the wafer 505 is switchedfor each beam under the control of the blanker array.

Since the charged-particle beam exposure apparatus of this embodimentadopts an excellent electrooptic system array as described above for thecorrection electrooptic system, an apparatus having a very high exposureprecision can be provided and can increase the integration degree of adevice to be manufactured in comparison with the prior art.

<Example of Semiconductor Production System>

A production system for a semiconductor device (semiconductor chip suchas an IC or LSI, liquid crystal panel, CCD, thin-film magnetic head,micromachine, or the like) using the exposure apparatus will beexemplified. A trouble remedy or periodic maintenance of a manufacturingapparatus installed in a semiconductor manufacturing factory, ormaintenance service such as software distribution is performed by usinga computer network outside the manufacturing factory.

FIG. 15 shows the overall system cut out at a given angle. In FIG. 15,reference numeral 1010 denotes a business office of a vendor (apparatussupply manufacturer) which provides a semiconductor device manufacturingapparatus. Assumed examples of the manufacturing apparatus aresemiconductor manufacturing apparatuses for various processes used in asemiconductor manufacturing factory, such as pre-process apparatuses(lithography apparatus including an exposure apparatus, resistprocessing apparatus, and etching apparatus, annealing apparatus, filmformation apparatus, planarization apparatus, and the like) andpost-process apparatuses (assembly apparatus, inspection apparatus, andthe like). The business office 1010 comprises a host management system1080 for providing a maintenance database for the manufacturingapparatus, a plurality of operation terminal computers 1100, and a LAN(Local Area Network) 1090 which connects the host management system 1080and computers 1100 to construct an intranet. The host management system1080 has a gateway for connecting the LAN 1090 to Internet 1050 as anexternal network of the business office, and a security function forlimiting external accesses.

Reference numerals 1020 to 1040 denote manufacturing factories of thesemiconductor manufacturer as users of manufacturing apparatuses. Themanufacturing factories 1020 to 1040 may belong to differentmanufacturers or the same manufacturer (pre-process factory,post-process factory, and the like). Each of the factories 1020 to 1040is equipped with a plurality of manufacturing apparatuses 1060, a LAN(Local Area Network) 1110 which connects these apparatuses 1060 toconstruct an intranet, and a host management system 1070 serving as amonitoring apparatus for monitoring the operation status of eachmanufacturing apparatus 1060. The host management system 1070 in each ofthe factories 1020 to 1040 has a gateway for connecting the LAN 1110 inthe factory to the Internet 1050 as an external network of the factory.Each factory can access the host management system 1080 of the vendor1010 from the LAN 1110 via the Internet 1050. Typically, the securityfunction of the host management system 1080 authorizes access of only alimited user to the host management system 1080.

In this system, the factory notifies the vender via the Internet 1050 ofstatus information (e.g., the symptom of a manufacturing apparatus introuble) representing the operation status of each manufacturingapparatus 1060. The vender transmits, to the factory, responseinformation (e.g., information designating a remedy against the trouble,or remedy software or data) corresponding to the notification, ormaintenance information such as the latest software or help information.Data communication between the factories 1020 to 1040 and the vender1010 and data communication via the LAN 1110 in each factory typicallyadopt a communication protocol (TCP/IP) generally used in the Internet.Instead of using the Internet as an external network of the factory, adedicated-line network (e.g., ISDN) having high security which inhibitsaccess of a third party can be adopted. It is also possible that theuser constructs a database in addition to one provided by the vendor andsets the database on an external network and that the host managementsystem authorizes access to the database from a plurality of userfactories.

FIG. 16 is a view showing the concept of the overall system of thisembodiment that is cut out at a different angle from FIG. 15. In theabove example, a plurality of user factories having manufacturingapparatuses and the management system of the manufacturing apparatusvendor are connected via an external network, and production managementof each factory or information of at least one manufacturing apparatusis communicated via the external network. In the example of FIG. 16, afactory having a plurality of manufacturing apparatuses of a pluralityof vendors, and the management systems of the vendors for thesemanufacturing apparatuses are connected via the external network of thefactory, and maintenance information of each manufacturing apparatus iscommunicated. In FIG. 16, reference numeral 2010 denotes a manufacturingfactory of a manufacturing apparatus user (semiconductor devicemanufacturer) where manufacturing apparatuses for various processes,e.g., an exposure apparatus 2020, resist processing apparatus 2030, andfilm formation apparatus 2040 are installed in the manufacturing line ofthe factory. FIG. 16 shows only one manufacturing factory 2010, but aplurality of factories are networked in practice. The respectiveapparatuses in the factory are connected to a LAN 2060 to construct anintranet, and a host management system 2050 manages the operation of themanufacturing line. The business offices of vendors (apparatus supplymanufacturers) such as an exposure apparatus manufacturer 2100, resistprocessing apparatus manufacturer 2200, and film formation apparatusmanufacturer 2300 comprise host management systems 2110, 2210, and 2310for executing remote maintenance for the supplied apparatuses. Each hostmanagement system has a maintenance database and a gateway for anexternal network, as described above. The host management system 2050for managing the apparatuses in the manufacturing factory of the user,and the management systems 2110, 2210, and 2310 of the vendors for therespective apparatuses are connected via the Internet or dedicated-linenetwork serving as an external network 2000. If a trouble occurs in anyone of a series of manufacturing apparatuses along the manufacturingline in this system, the operation of the manufacturing line stops. Thistrouble can be quickly solved by remote maintenance from the vendor ofthe apparatus in trouble via the external network 2000. This canminimize the stop of the manufacturing line.

Each manufacturing apparatus in the semiconductor manufacturing factorycomprises a display, a network interface, and a computer for executingnetwork access software and apparatus operating software which arestored in a storage device. The storage device is a built-in memory,hard disk, or network file server. The network access software includesa dedicated or general-purpose web browser, and provides a userinterface having a window as shown in FIG. 17 on the display. Whilereferring to this window, the operator who manages manufacturingapparatuses in each factory inputs, in input items on the windows,pieces of information such as the type of manufacturing apparatus(4010), serial number (4020), subject of trouble (4030), occurrence date(4040), degree of urgency (4050), symptom (4060), remedy (4070), andprogress (4080). The pieces of input information are transmitted to themaintenance database via the Internet, and appropriate maintenanceinformation is sent back from the maintenance database and displayed onthe display. The user interface provided by the web browser realizeshyperlink functions (4100 to 4120), as shown in FIG. 17. This allows theoperator to access detailed information of each item, receive thelatest-version software to be used for a manufacturing apparatus from asoftware library provided by a vendor, and receive an operation guide(help information) as a reference for the operator in the factory.

A semiconductor device manufacturing process using the above-describedproduction system will be explained. FIG. 18 shows the flow of the wholemanufacturing process of the semiconductor device. In step 1 (circuitdesign), a semiconductor device circuit is designed. In step 2 (creationof exposure control data), exposure control data of the exposureapparatus is created based on the designed circuit pattern. In step 3(wafer manufacture), a wafer is manufactured using a material such assilicon. In step 4 (wafer process) called a pre-process, an actualcircuit is formed on the wafer by lithography using a prepared mask andthe wafer. Step 5 (assembly) called a post-process is the step offorming a semiconductor chip by using the wafer manufactured in step 4,and includes an assembly process (dicing and bonding) and packagingprocess (chip encapsulation). In step 6 (inspection), inspections suchas the operation confirmation test and durability test of thesemiconductor device manufactured in step 5 are conducted. After thesesteps, the semiconductor device is completed and shipped (step 7). Forexample, the pre-process and post-process may be performed in separatededicated factories. In this case, maintenance is done for each of thefactories by the above-described remote maintenance system. Informationfor production management and apparatus maintenance is communicatedbetween the pre-process factory and the post-process factory via theInternet or dedicated-line network.

FIG. 19 shows the detailed flow of the wafer process. In step 11(oxidation), the wafer surface is oxidized. In step 12 (CVD), aninsulating film is formed on the wafer surface. In step 13 (electrodeformation), an electrode is formed on the wafer by vapor deposition. Instep 14 (ion implantation), ions are implanted in the wafer. In step 15(resist processing), a photosensitive agent is applied to the wafer. Instep 16 (exposure), the above-mentioned exposure apparatus draws(exposes) a circuit pattern on the wafer. In step 17 (developing), theexposed wafer is developed. In step 18 (etching), the resist is etchedexcept for the developed resist image. In step 19 (resist removal), anunnecessary resist after etching is removed. These steps are repeated toform multiple circuit patterns on the wafer. A manufacturing apparatusused in each step undergoes maintenance by the remote maintenancesystem, which prevents a trouble in advance. Even if a trouble occurs,the manufacturing apparatus can be quickly recovered. The productivityof the semiconductor device can be increased in comparison with theprior art.

The present invention can provide, e.g., an electrooptic system arraywhich solves crosstalk unique to a multi-beam and realizes variousconditions such as downsizing, high precision, and high reliability athigh level. The present invention can also provide a high-precisionexposure apparatus using the electrooptic system array, ahigh-productivity device manufacturing method, a semiconductor deviceproduction factory, and the like.

As many apparently widely different embodiments of the present inventioncan be made without departing from the spirit and scope thereof, it isto be understood that the invention is not limited to the specificembodiments thereof except as defined in the appended claims.

1. An electrooptic system for charged-particle beams, the systemcomprising: a first layer having a plurality of first apertures throughwhich the charged-particle beams pass; a second layer having a pluralityof second apertures through which the charged-particle beams pass and aplurality of electrodes; and a conductive shield layer interposedbetween the first layer and the second layer.
 2. The system according toclaim 1, wherein the conductive shield layer has a plurality of thirdapertures through which the charged-particle beams pass.
 3. The systemaccording to claim 2, wherein a size of the third aperture is largerthan that of the first aperture or the second aperture.
 4. The systemaccording to claim 1, wherein the conductive shield layer is arranged tobe substantially parallel to the first layer and the second layer. 5.The system according to claim 1, wherein a thickness of the conductiveshield layer is thicker than that of the first layer or the secondlayer.
 6. The system according to claim 1, further comprising aninsulating layer interposed between the first layer and the conductiveshield layer.
 7. The apparatus according to claim 1, wherein the secondlayer is insulated from the conductive shield layer.
 8. An electroopticsystem for charged-particle beams, the system comprising: an upper layerhaving a plurality of first apertures through which the charged-particlebeams pass; a middle layer having a plurality of second aperturesthrough which the charged-particle beams pass and a plurality ofelectrodes; a lower layer having a plurality of third apertures throughwhich the charged-particle beams pass; a first conductive shield layerinterposed between the upper layer and the middle layer; and a secondconductive shield layer interposed between the middle layer and thelower layer.
 9. The system according to claim 8, wherein the pluralityof electrodes are grouped in units of rows running along a firstdirection.
 10. The system according to claim 8, wherein a first intervalbetween the middle layer and the first conductive shield layer and asecond interval between the middle layer and the second conductiveshield layer are smaller than a layout pitch of the plurality ofelectrodes.
 11. An electrooptic system for charged-particle beams, thesystem comprising: first and second electrooptic systems each includingan upper layer, a middle layer, a lower layer, a first conductive shieldlayer interposed between the upper layer and the middle layer, and asecond conductive shield layer interposed between the middle layer andthe lower layer, the upper layer having a plurality of first aperturesthrough which the charged-particle beams pass, the middle layer having aplurality of second apertures through which the charged-particle beamspass and a plurality of electrodes, the lower layer having a pluralityof third apertures through which the charged-particle beams pass. 12.The system according to claim 11, wherein the plurality of electrodes ofthe first electrooptic system are grouped in units of rows running alonga first direction and the plurality of electrodes of the secondelectrooptic system are grouped in units of rows running along a seconddirection perpendicular to the first direction.
 13. The system accordingto claim 11, wherein the lower layer of the first electrooptic systemand the upper layer of the second electrooptic system are formed as onelayer.